Azo dyestuffs.



UNITED STATES PATENT ()FFQ AUGUST BLANK ANB Wr HELM BEaeno T, or LEVERKUSEN, NEAR COLOGNE, enn- MANY, ASSIGNORS T0 FARBENFABRIKEN VORM. ramps. BAYER & 00., or "mama FIELD, GERMANY, A CORFORATION or GERMANY.

No Drawing.

To all whom it may concern:

Be it known that we, AUoUsr BLANK and. \YILHEL BERoooL'r, doctors of philosophy, chemists, citizens of the German Empire, residing at Leverkusen, near Cologne-on-the- Rhine, Germany, have invented new and useful Improvements in New Azo Dyestuffs,

of which the following is a specification.

Our invention relates to the manufacture and production of new blue azo dyestuffs suitable for dyeing half-wool which are distinguished by the valuable property that they dye cotton an intense shade, whereas they leave the wool almost untinged in a neutral dye-bath. The dyeing is carried out in the usual way with an addition of Glauber salt. The colors dye easily level. Most of the half-wool or substantive 16S hitherto known display the tendency, on being worked for an extended time at the boil, to dye the wool a deeper shade than the cotton, This is a decided drawback for the dyeing of the half-wool and can be over come only by regulating the temperature most carefully. This disadvantage is excluded by the use of our new dyes, which always dye the cotton considerably deeper than the wool even when the boiling is continued for a long time, so that the wool can easily be shaded as desired with suitable neutral-dyeing colors.

The process for producing our new dyes consists in combining a tetrazotizcd para diamin, such as para-phenylenediamin, dianisidin or para-diaminoazo compounds, such as para-phenylenedia1nin+one molecule of a naphthylamin-sulfonic acid with 5.5 dioxy-2.2-dinaphthylamin-7-7-disulfonic acid:

so,n /W/NH\ so,H K Rn H and one molecule of a 1.8-dioxynaphthalene sulfonic acid.

The new azo coloring matters are in the shape of their alkaline salts after being dried and pulverized dark powders soluble in water with a blue coloration. Upon reduction with stannous chlorid and hydrochloric acid a para-diamin, 1.8-dioxy-2- na1 hthylam1n-sulfon1c acid and G-annno- Specification oi etters Patent.

Application filed March 28.

salt.

5.5 dioxy-22-dinaphthylamin-7.7-disulfonic v Patented Dec. 30, N13. 5913. Serial No. 757,351.

icid are obtained. They dye cotton, silk, artificial silk and half-silk or half-wool blue shades, when applied on the two last men tioned materials they leave the wool or silk 1 almost untinged.

lene-flb-disulfonic acid containing parts of soda. The production of the intermediate compound is completed after a short time. Subsequently a solution of the sodium salt obtained from 46 parts of 5.5-dioXy2.2-di

naphthylamin-T'Z-disa ifonic acid containing 60 parts of soda is added, the mixture is stirred during 12 hours, heated to C. and the dye is precipitated with common It dyes cotton pure reddish-blue shades. It is after-being dried and pulverized in the shape of its sodium salt a dark .powder soluble in water with a blue color and yielding upon reduction with stannous chlorid and hydrochloric acid'dianisidin,1.8- dioxy 2 naphthylamin 3.6 disulfonic acid and G-aminodioxy- 2.2-dinapht-hylamin- 7.7disulfonic acid. It has most probably the formula (free acid):

Other 1.8 dioxynaphthalene sulfonic acids, such as the 4-monosulfonic acid may be used.

We claim 1. The herein described new azo dyestuffs, which are in the shape of their alkaline salts, after being dried and pulverized, dark powders soluble in water with av blue coloration; yielding upon reduction with stannous chlorid and hydrochloricacidapara-diamin, 1.8-dioxy-2-naphthylamin sulfonicacid and G-amino- 5.5 dioxy 2.2 dinaphthylamin-7.7-

disulfonic acid; dyeing cotton, sill ,artificial silk, half-silk andhalf-wool blue shades and being distinguished by the valuable property that on dyeing half-wool they dye cotton an intense shade, whereas they leave the WOOl almost untinged in a neutral dyebath, substantially as described. i

2. The herein described new azo dyestuil having most probably the formula:

which is after being dried and pulverized in the shape of its sodium salt a dark powder soluble in Water with a blue color; yielding upon reduction with stannous chlorid 25 and hydrochloric acid dianisidin, 1.8-dioxy- 2-naphthylaniin-3.6-disulfonic acid and G-amino (boxy-2.2-dinaphthyla1nin-7.7- disulfonio acid; and dyeing cotton in pure reddish-blue shades, substantially as de scribed.

In testimony whereof We have hereunto set our hands in the presence of two subscribing Witnesses. 4

AUGUST BLANK. VILHELM BERGDOLT.

L. s.] [1,. s.]

Witnesses HELEN NUFER, ALBERT NUFER. 

